Security agencies are keeping a watch on 13 Pakistani Facebook accounts and 1,100 users who are on their friends’ lists, as part of a probe into social media trap by the Pakistan’s Inter Services Intelligence (ISI).

The Uttar Pradesh Anti-Terrorist Squad (ATS) investigators had zeroed in on 13 Facebook accounts which are suspected to be operated by ISI, a senior official associated with the probe said.

The ATS came across these accounts while scanning hundreds of Facebook profiles after the arrest of BrahMos aerospace engineer Nishant Agarwal and BSF jawan Achuytanand Mishra, who was allegedly ‘honey-trapped’ by ISI over Facebook, he said.

“The ATS has also zeroed in on around 1,100 users that are on the friends’ lists of the suspicious accounts. The process of cross-checking the credentials of people on the friends’ lists is already on,” said Asim Arun, IG, UP ATS.

He said that 1,100 Facebook account users had been segregated into three categories — those related to defence and armed forces, those posted in important and sensitive installations, and general users.

The IG said it was mandatory to approach each user in the first category to ascertain whether they shared any information knowingly or unknowingly.

The process of questioning the second category users was also on while the third category users were being examined and would be questioned, if anything was found suspicious.

He said there were possibilities that other users on the friends’ lists of the suspected accounts may have shared some crucial details related to national security.

Moreover, the Facebook users, who have been approached by the ATS, were being alerted about the ISI traps for extraction of information, he said.

On October 11, the UP ATS had arrested Brahmos engineer Nishant Agarwal from his Nagpur residence on charges of espionage. He allegedly leaked crucial information to two ISI-operated Facebook account users after befriending them.

BSF jawan Achyutanand Mishra, who was arrested from Noida on September 19, was ‘honey-trapped’ by a similar fake Facebook account being operated reportedly by the ISI. He was accused of sharing crucial information about armed forces and movement of troops with a Facebook friend. He allegedly also chatted with a woman on WhatsApp who used a mobile number registered in Pakistan.